Use operator bool to claw back some readability

Author: CodaFi

include/swift/AST/ProtocolConformanceRef.h

@@ -63,14 +63,19 @@ class ProtocolConformanceRef {
            "cannot construct ProtocolConformanceRef with null");
   }
 
+  ProtocolConformanceRef(std::nullptr_t = nullptr)
+      : Union((ProtocolDecl *)nullptr) {}
+
   static ProtocolConformanceRef forInvalid() {
-    return ProtocolConformanceRef(UnionType((ProtocolDecl *)nullptr));
+    return ProtocolConformanceRef();
   }
 
   bool isInvalid() const {
     return !Union;
   }
 
+  explicit operator bool() const { return !isInvalid(); }
+
   /// Create either a concrete or an abstract protocol conformance reference,
   /// depending on whether ProtocolConformance is null.
   explicit ProtocolConformanceRef(ProtocolDecl *protocol,

lib/AST/ASTContext.cpp

@@ -3168,8 +3168,8 @@ void SILFunctionType::Profile(
   if (errorResult) errorResult->profile(id);
   id.AddBoolean(isGenericSignatureImplied);
   substitutions.profile(id);
-  id.AddBoolean(!conformance.isInvalid());
-  if (!conformance.isInvalid())
+  id.AddBoolean((bool)conformance);
+  if (conformance)
     id.AddPointer(conformance.getRequirement());
 }
 
@@ -4167,7 +4167,7 @@ ASTContext::getForeignRepresentationInfo(NominalTypeDecl *nominal,
             = getProtocol(KnownProtocolKind::ObjectiveCBridgeable)) {
         auto conformance = dc->getParentModule()->lookupConformance(
             nominal->getDeclaredType(), objcBridgeable);
-        if (!conformance.isInvalid()) {
+        if (conformance) {
           result =
               ForeignRepresentationInfo::forBridged(conformance.getConcrete());
         }
@@ -4320,8 +4320,8 @@ Type ASTContext::getBridgedToObjC(const DeclContext *dc, Type type,
   };
 
   // Do we conform to _ObjectiveCBridgeable?
-  auto conformance = findConformance(KnownProtocolKind::ObjectiveCBridgeable);
-  if (!conformance.isInvalid()) {
+  if (auto conformance =
+          findConformance(KnownProtocolKind::ObjectiveCBridgeable)) {
     // The corresponding value type is... the type.
     if (bridgedValueType)
       *bridgedValueType = type;
@@ -4331,7 +4331,7 @@ Type ASTContext::getBridgedToObjC(const DeclContext *dc, Type type,
   }
 
   // Do we conform to Error?
-  if (!findConformance(KnownProtocolKind::Error).isInvalid()) {
+  if (findConformance(KnownProtocolKind::Error)) {
     // The corresponding value type is Error.
     if (bridgedValueType)
       *bridgedValueType = getErrorDecl()->getDeclaredInterfaceType();
@@ -4465,8 +4465,7 @@ ASTContext::getOverrideGenericSignature(const ValueDecl *base,
   auto lookupConformanceFn =
       [&](CanType depTy, Type substTy,
           ProtocolDecl *proto) -> ProtocolConformanceRef {
-    auto conf = subMap.lookupConformance(depTy, proto);
-    if (!conf.isInvalid())
+    if (auto conf = subMap.lookupConformance(depTy, proto))
       return conf;
 
     return ProtocolConformanceRef(proto);

lib/AST/GenericSignature.cpp

@@ -536,9 +536,8 @@ bool GenericSignatureImpl::isRequirementSatisfied(Requirement requirement) {
     if (canFirstType->isTypeParameter())
       return conformsToProtocol(canFirstType, protocol);
     else
-      return !GSB->lookupConformance(/*dependentType=*/CanType(), canFirstType,
-                                     protocol)
-                  .isInvalid();
+      return (bool)GSB->lookupConformance(/*dependentType=*/CanType(),
+                                          canFirstType, protocol);
   }
 
   case RequirementKind::SameType: {

lib/AST/GenericSignatureBuilder.cpp

@@ -4416,8 +4416,8 @@ ConstraintResult GenericSignatureBuilder::addTypeRequirement(
         auto conformance =
             getLookupConformanceFn()(dependentType, subjectType, proto->getDecl());
 
-        // FIXME: diagnose if there's an invalid conformance.
-        if (!conformance.isInvalid()) {
+        // FIXME: diagnose if there's no conformance.
+        if (conformance) {
           if (addConditionalRequirements(conformance, inferForModule,
                                          source.getLoc()))
             return ConstraintResult::Conflicting;

lib/AST/Module.cpp

@@ -748,8 +748,7 @@ ModuleDecl::lookupExistentialConformance(Type type, ProtocolDecl *protocol) {
   // If the existential is class-constrained, the class might conform
   // concretely.
   if (auto superclass = layout.explicitSuperclass) {
-    auto result = lookupConformance(superclass, protocol);
-    if (!result.isInvalid())
+    if (auto result = lookupConformance(superclass, protocol))
       return result;
   }
 
@@ -765,8 +764,7 @@ ModuleDecl::lookupExistentialConformance(Type type, ProtocolDecl *protocol) {
     // If the protocol has a superclass constraint, we might conform
     // concretely.
     if (auto superclass = protoDecl->getSuperclass()) {
-      auto result = lookupConformance(superclass, protocol);
-      if (!result.isInvalid())
+      if (auto result = lookupConformance(superclass, protocol))
         return result;
     }
 
@@ -800,8 +798,7 @@ ProtocolConformanceRef ModuleDecl::lookupConformance(Type type,
     // able to be resolved by a substitution that makes the archetype
     // concrete.
     if (auto super = archetype->getSuperclass()) {
-      auto inheritedConformance = lookupConformance(super, protocol);
-      if (!inheritedConformance.isInvalid()) {
+      if (auto inheritedConformance = lookupConformance(super, protocol)) {
         return ProtocolConformanceRef(ctx.getInheritedConformance(
             type, inheritedConformance.getConcrete()));
       }
@@ -860,7 +857,7 @@ ProtocolConformanceRef ModuleDecl::lookupConformance(Type type,
 
     // Compute the conformance for the inherited type.
     auto inheritedConformance = lookupConformance(superclassTy, protocol);
-    assert(!inheritedConformance.isInvalid() &&
+    assert(inheritedConformance &&
            "We already found the inherited conformance");
 
     // Create the inherited conformance entry.

lib/AST/ProtocolConformance.cpp

@@ -131,7 +131,7 @@ ProtocolConformanceRef::subst(Type origType,
     auto optConformance =
         proto->getModuleContext()->lookupExistentialConformance(substType,
                                                                 proto);
-    if (!optConformance.isInvalid())
+    if (optConformance)
       return optConformance;
 
     return ProtocolConformanceRef::forInvalid();

lib/AST/SubstitutionMap.cpp

@@ -355,8 +355,7 @@ SubstitutionMap::lookupConformance(CanType type, ProtocolDecl *proto) const {
   // Check whether the superclass conforms.
   if (auto superclass = genericSig->getSuperclassBound(type)) {
     LookUpConformanceInSignature lookup(getGenericSignature().getPointer());
-    auto conformance = lookup(type->getCanonicalType(), superclass, proto);
-    if (!conformance.isInvalid())
+    if (auto conformance = lookup(type->getCanonicalType(), superclass, proto))
       return conformance;
   }
 

lib/IDE/ConformingMethodList.cpp

@@ -141,7 +141,7 @@ void ConformingMethodListCallbacks::getMatchingMethods(
 
       // The return type conforms to any of the requested protocols.
       for (auto Proto : ExpectedTypes) {
-        if (!CurModule->conformsToProtocol(declTy, Proto).isInvalid())
+        if (CurModule->conformsToProtocol(declTy, Proto))
           return true;
       }
 

lib/IDE/IDETypeChecking.cpp

@@ -619,7 +619,7 @@ class ExpressionTypeCollector: public SourceEntityWalker {
 
     // Collecting protocols conformed by this expressions that are in the list.
     for (auto Proto: InterestedProtocols) {
-      if (!Module.conformsToProtocol(E->getType(), Proto.first).isInvalid()) {
+      if (Module.conformsToProtocol(E->getType(), Proto.first)) {
         Conformances.push_back(Proto.second);
       }
     }

lib/IRGen/GenProto.cpp

@@ -956,8 +956,7 @@ emitConditionalConformancesBuffer(IRGenFunction &IGF,
       rootConformance, [&](unsigned, CanType type, ProtocolDecl *proto) {
         auto substType = type.subst(subMap)->getCanonicalType();
         auto reqConformance = subMap.lookupConformance(type, proto);
-        assert(!reqConformance.isInvalid() &&
-               "conditional conformance must be valid");
+        assert(reqConformance && "conditional conformance must be valid");
 
         tables.push_back(emitWitnessTableRef(IGF, substType, reqConformance));
         return /*finished?*/ false;